CONSERVATION OF FEEDING-STUFFS 133 



The losses due to respiration fall chiefly upon 

 the starch, which must previously be converted 

 into sugar. Such a formation of sugar takes place 

 uninterruptedly in the living tubers, but this is not 

 so easy to prove at higher temperature as it is 

 immediately used up in the process of respiration. 

 If, however, respiration is diminished by keeping 

 the potatoes at a low temperature, the sugar is 

 not completely destroyed, a portion remains over. 

 As the change of starch into sugar is not prevented 

 by low temperature, the potatoes under these con- 

 ditions become sweet owing to the storage of the 

 sugar. The extent of this increase is shown in an 

 experiment where potatoes were kept for a long 

 time at o C. , and it was observed that after 



3 days .... 0-51 gr., sugar 



5 - 1-25 



10 .... 2-65 

 20 .... 7-52 



30 ,, 18-53 



50 .... 267 



59 30-3 



At 3 C. the increase in sugar was muchjmore 

 gradual, so that after 50 days only 579 gr. were 

 found. At 8-10 there was no storage of sugar at 

 all. 



If potatoes which have become sweet at a low 

 temperature are brought into a warm place the 



